1. Field of the Invention
The present invention relates to the field of semiconductor devices containing an integrated circuit chip.
2. Description of the Related Art
Known semiconductor devices comprise an electrical connection support plate having electrical connection regions on a front face, an integrated circuit chip placed at a certain distance from the front face of the support plate and provided with electrical connection pads located so as to face the electrical connection regions of the support plate, electrical connection balls interposed between and soldered to the pads on the chip and the regions of the support plate, and also an electrically non-conducting fill material that fills the space between the support plate and the integrated circuit chip, embedding the electrical connection balls. Furthermore, it is common practice for the front face of the support plate to be provided with a protective interlayer, generally a varnish, in which apertures are provided, at least partly exposing the electrical connection regions.
To fabricate such semiconductor devices, a drop of fill material is deposited on the support plate approximately in the middle of the location that the integrated chip will occupy. Next, the integrated circuit chip provided beforehand with electrical connection balls on these pads is put into place, the movement of the integrated circuit chip approaching the support plate causing the drop of the fill material to spread out. Next, the electrical connection balls are soldered to the regions of the support plate and the fill material is cured.
It has been observed that, as the fill material spreads out, air bubbles or micro bubbles are trapped in this fill material, especially on or near the electrical connection balls and mainly in the local apertures left in the protective interlayer above the electrical connection regions of the support plate.
Such trapped bubbles lower the mechanical strength, weaken the electrical connections between the integrated circuit chip and the support plate via the electrical connection balls and, in general, reduce the quality of the semiconductor devices obtained
Accordingly, there exists a need for overcoming the disadvantages of the prior art as discussed above.